Ice-making appliances and methods for dispensing ice above a sink

ABSTRACT

An ice-making appliance, as provided herein, may include a sink, an upper dispenser, a lower tank, and a heat exchanger. The upper dispenser may be disposed above the sink. The lower tank may be disposed below the upper dispenser to hold an initial volume of liquid water. The heat exchanger may include a mold finger may be disposed within the lower tank and to freeze a portion of the initial volume of liquid water as an ice nugget. The lower tank may define a vertical passage permitting the ice nugget to float therethrough with a remaining volume of liquid water. The upper dispenser may include an ice door. The ice door may be movable between a closed position and an open position. The open position may permit the ice nugget from the upper dispenser to the sink. Methods of operating the ice-making appliance are also provided herein.

FIELD OF THE INVENTION

The present subject matter relates generally to ice making, and more particularly to ice-making appliances to dispense ice above a residential or commercial sink.

BACKGROUND OF THE INVENTION

Ice-making appliances or ice makers generally produce ice for the use of consumers, such as in drinks being consumed, for cooling foods or for other various purposes. Certain refrigerator appliances include ice makers for producing ice. The ice maker can be disposed within the appliance's freezer chamber and direct ice into an ice bucket where it can be stored within the freezer chamber. Such refrigerator appliances can also include a dispensing system for assisting a user with accessing ice produced by the refrigerator appliance's ice maker. Nonetheless, the incorporation of ice makers into refrigerator appliances can have drawbacks, such as limits on the amount of ice that can be produced and the reliance on the refrigeration system of the refrigerator appliance to form the ice. Difficulties can also arise in providing plumbing to connect a water source or drain to the refrigerator appliance. Furthermore, the aesthetics or “clean appearance” of a refrigerator appliance may be negatively impacted by the presence of an ice maker or dispenser.

Dedicated or stand-alone ice makers have also been developed. These ice makers are separate from refrigerator appliances and provide independent ice supplies. Generally, ice is provided into an interior volume for storage. This can present its own difficulties with maintaining the ice. For instance, such systems may become especially heavy or bulky. Moreover, if any ice within the interior volume has melted, it may be difficult to remove the liquefied ice or water. Additionally or alternatively, difficulties may arise when trying to add water to the system for producing ice (e.g., without inadvertently spilling water outside the ice maker or within an undesired interior portion of the ice maker).

In many ice makers, water begins to freeze within a dedicated mold body and solidify first from its sides and outer surfaces (including a top water surface that may be directly exposed to freezing air), and then through the remaining volume of water occupying the cavity. In other words, the exterior surfaces of an ice cube freeze first. However, impurities and gases contained within the water to be frozen may be trapped in a solidified ice cube during the freezing process. For example, impurities and gases may be trapped near the center or the bottom surface of the ice cube, due to their inability to escape and as a result of the freezing liquid to solid phase change of the ice cube surfaces. Separate from or in addition to the trapped impurities and gases, a dull or cloudy finish may form on the exterior surfaces of an ice cube (e.g., during rapid freezing of the ice cube). Generally, a cloudy or opaque ice cube is the resulting product of typical ice making appliances.

Accordingly, further improvements in the field of ice making would be desirable. In particular, it may be desirable to provide an appliance or methods for rapidly and reliably producing substantially clear ice apart from a refrigerator appliance. Furthermore, it may be desirable to provide an appliance which does not require significant space or plumbing to handle ice and water therein.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

In one exemplary aspect of the present disclosure, an ice-making appliance is provided. The ice-making appliance may include a sink, an upper dispenser, a lower tank, and a heat exchanger. The upper dispenser may be disposed above the sink. The lower tank may be disposed below the upper dispenser to hold an initial volume of liquid water upstream from the upper dispenser. The heat exchanger may include a mold finger may be disposed within the lower tank and to freeze a portion of the initial volume of liquid water as an ice nugget. The lower tank may define a vertical passage permitting the ice nugget to float therethrough with a remaining volume of liquid water. The upper dispenser may include an ice door. The ice door may be movable between a closed position and an open position. The open position may permit the ice nugget from the upper dispenser to the sink.

In another exemplary aspect of the present disclosure, method of dispensing ice is provided. The method may include supplying an initial volume of liquid water to a lower tank. The method may further include freezing a portion of the initial volume of liquid water as an ice nugget on the mold finger within a remaining volume of the initial volume of liquid water. The method may still further include releasing the ice nugget from the mold finger, and permitting the ice nugget to float upward from the mold finger to the upper dispenser.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

FIG. 1 provides a perspective view of an ice-making appliance according to exemplary embodiments of the present disclosure.

FIG. 2 provides a schematic, sectional view of an ice-making appliance according to exemplary embodiments of the present disclosure.

FIG. 3 provides a schematic, elevation view of a heat exchanger of the exemplary ice-making appliance of FIG. 2 prior to freezing of an ice-making cycle.

FIG. 4 provides a schematic, elevation view of a heat exchanger of the exemplary ice-making appliance of FIG. 2 during freezing of an ice-making cycle.

FIG. 5 provides a schematic, elevation view of a heat exchanger of the exemplary ice-making appliance of FIG. 2 subsequent to freezing of an ice-making cycle.

FIG. 6 provides a schematic, sectional view of a portion of an ice-making appliance according to exemplary embodiments of the present disclosure.

FIG. 7 provides a flow chart illustration a method of operating an ice-making appliance according to exemplary embodiments of the present disclosure.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

As used herein, the term “or” is generally intended to be inclusive (i.e., “A or B” is intended to mean “A or B or both”). The terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “upstream” and “downstream” refer to the relative flow direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the flow direction from which the fluid flows, and “downstream” refers to the flow direction to which the fluid flows.

Turning now to the figures, FIGS. 1 and 2 illustrate an ice-making appliance 100 according to exemplary embodiments of the present disclosure. Specifically, FIG. 1 provides a perspective view illustrating an upper dispenser 110 and a sink 114, such as a typical residential or commercial kitchen sink having a drain, to which upper dispenser 110 may be directed (e.g., for the dispensing of ice nuggets 116 or a water flow 118). FIG. 2 provides a schematic, elevation view of ice-making appliance 100, including a lower tank 112 below upper dispenser 110.

Generally, ice-making appliance 100 defines a vertical direction V. As shown, upper dispenser 110 is disposed above lower tank 112. At least a portion of sink 114 may be further disposed below upper dispenser 110, and an additional or alternative portion of sink 114 may be disposed above lower tank 112. In some embodiments, upper dispenser 110 is mounted to a counter 120 adjacent to sink 114. For instance, upper dispenser 110 may extend vertically upward away from a top surface 122 of counter 120. Lower tank 112 may be mounted or generally disposed below counter 120 while still being in (e.g., upstream) fluid communication with upper dispenser 110. Thus, a conduit or portion of lower tank 112 may extend through counter 120 from bottom surface 124 to top surface 122. Nonetheless, it is understood that additional or alternative embodiments of ice-making appliance 100 may fluidly connect lower tank 112 to upper dispenser 110 without passing through counter 120 (e.g., by routing a connecting conduit around counter 120 or through a proximate wall).

Lower tank 112 defines an internally-open or unobstructed chamber 126 (e.g., free of any auger or mechanical conveyer mechanism) for enclosing ice and liquid water upstream from upper dispenser 110. For instance, lower tank 112 may hold an initial volume of liquid water within the chamber 126 prior to freezing any water or generating any ice nuggets 116. In some embodiments, water (e.g., the initial volume of liquid water) can be selectively supplied to the chamber 126 from a water source, such as a municipal water supply or well. A water supply valve 128 disposed outside of chamber 126 in upstream fluid communication with lower tank 112 may be opened and closed to control the flow of liquid water from the water source.

A heat exchanger 130 having one or more mold fingers 136 is provided on or adjacent to lower tank 112 (e.g., at a bottom portion of lower tank 112). When assembled, the mold finger(s) 136 are generally disposed within lower tank 112. For instance, the mold finger(s) 136 may extend upward within chamber 126 from a bottom portion of lower tank 112. Optionally, the mold finger(s) 136 may extend from (e.g., in conductive thermal communication) an exchange base 132. In some such embodiments, heat exchanger has a hot side 134 disposed opposite of mold finger(s) 136 and outside of the chamber 126 or lower tank 112, generally. Additionally or alternatively, mold finger(s) 136 may be disposed below sink 114 (e.g., below sidewall or bottom wall of sink 114). If multiple mold fingers 136 are provided, each may be spaced apart from each other (e.g., horizontally in a direction perpendicular to the vertical direction V).

Turning briefly to FIGS. 3 through 5, during use, such as during an ice-making cycle, a mold finger 136 can be surrounded by or extend through a portion of the liquid water within lower tank 112. Prior to freezing, the mold finger 136 contacts surrounding liquid water, as illustrated in FIG. 3. As is described below, heat may be drawn from the surrounding water through the mold finger 136 and exchange base 132. Portions of the liquid water may collect and freeze outwardly about the mold finger 136 to form an ice nugget 116, as illustrated in FIG. 4. After the ice nugget 116 has been formed on the mold finger 136 (e.g., subsequent to freezing), the ice nugget 116 may be released or separated from mold finger 136 to float upward within the remaining volume of liquid water in chamber 126, as illustrated in FIG. 5. For instance, heat may be conducted to mold finger 136 such that a small inner layer of ice nugget 116 melts against mold finger 136. Optionally, an additional volume of liquid water may be added to chamber 126 to further lift released ice nuggets 116 to or through upper dispenser 110 (FIG. 2). Advantageously, ice nugget 116 freezes from the inside out such that impurities or sediment within the chamber 126 may be progressively pushed outward (e.g., away from mold finger) and prevented from freezing within ice nugget 116.

Returning to FIG. 2, in optional embodiments a pump 137 is provided in fluid communication with the chamber 126 of lower tank 112. For instance, pump 137 may be disposed within the lower tank 112 to selectively circulate water through or within chamber 126. During freezing, the pump 137 may thus be activated to motivate a circulation flow of water (e.g., the initial or remaining volume of liquid water) within chamber 126, such as across mold finger(s) 136. Advantageously, the circulation flow may displace impurities or sediments as ice nugget 116 forms, thereby preventing such impurities or sediments from accumulating within ice nugget 116, especially during rapid freezing.

As shown, the lower tank 112 may define a vertical passage 138 (e.g., open passage) above mold finger 136 and below upper dispenser 110. During use, water may fill vertical passage 138 and chamber 126. Released or separated ice nuggets 116 may thus be permitted to float upward (e.g., with the remaining liquid water) through vertical passage 138. Water may further fill an internal passage 140 of upper dispenser 110, which extends above and downstream from vertical passage 138.

From vertical passage 138, ice nuggets 116 may thus be permitted to float with a remaining volume of liquid water into the internal passage 140 of upper dispenser 110. Advantageously, ice nuggets 116 may be conveyed via buoyancy to upper dispenser 110 without the need for an active auger or conveyor mechanism.

Generally, the freezing or releasing of ice nugget(s) 116 may be controlled according to a set freeze time or based on signals received from one or more sensors (e.g., temperature sensors) within lower tank 112. In some embodiments, operation of ice-making appliance 100 can be regulated by a controller 142 that is operative (e.g., electrical or wireless) communication with heat exchanger 130 or various other components. Controller 142 may include a memory (e.g., non-transitive media) and one or more microprocessors, CPUs or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of ice-making appliance 100. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In certain embodiments, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor. Alternatively, controller 142 may be constructed without using a microprocessor (e.g., using a combination of discrete analog or digital logic circuitry; such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.

Controller 142 may be disposed in a variety of locations; such as outside of chamber 126 on or below counter 120, sink 114, or upper dispenser 110. When assembled, input/output (“I/O”) signals may be routed between controller 142 and various operational components of ice-making appliance 100. For example, a user interface having one or more controls for directing operation of ice-making appliance 100 may be in operative communication with controller 142 via one or more signal lines or shared communication busses.

As illustrated, controller 142 may be in communication with the various components of ice-making appliance 100 and may control operation of the various components. For example, various pumps, valves, switches, etc. may be actuatable based on commands from the controller 142. As discussed, a user interface may additionally be in communication with the controller 142. Thus, the various operations may occur based on user input or automatically through controller 142 instruction.

In certain embodiments, heat exchanger 130 includes a Peltier cell 144. Peltier cell 144 may be mounted on, or as part of, exchange base 132. Generally, Peltier cell 144 includes a first end 146 and a second end 148, which exchange heat between them. First end 146 may be proximate to mold finger 136 while second end 148 is distal to mold finger 136 (e.g., proximal to hot side 134). When assembled, first end 146 is in conductive thermal communication with mold finger 136. During the freezing of ice nuggets 116, heat may thus be drawn from or transmitted to mold finger 136 from first end 146. As is understood, first end 146 is operable to exchange heat with second end 148 (e.g., based on a received direct current (DC) electrical current or voltage). The exchange of heat may be controlled, for instance, by controller 142. During freezing operations for forming ice nugget(s) 116 on mold finger(s) 136, Peltier cell 144 may be activated to direct heat from first end 146 to second end 148. Thus, first end 146 may act as the cold end while second end 148 acts as the hot end. During releasing operations for releasing ice nugget(s) 116 on mold finger(s) 136, Peltier cell 144 may be activated to direct heat from second end 148 to first end 146. Thus, first end 146 may act as the hot end and compel ice nugget 116 to separate from mold finger 136 while second end 148 acts as the cold end.

Turning now to FIG. 6, additional or alternative embodiments of ice-making appliance 100 include a sealed refrigeration system 150 with heat exchanger 130. In some embodiments, ice-making appliance 100 includes a sealed refrigeration system 150 for executing a vapor compression cycle for cooling within ice-making appliance 100 (e.g., within chamber 126). Sealed refrigeration system 150 includes a compressor 152, a condenser 154, an expansion device 156, and an evaporator 158 connected in fluid series on a sealed refrigeration loop charged with a refrigerant. When assembled the sealed refrigeration loop of sealed refrigeration system 150 is fluidly isolated from the lower tank 112 (e.g., such that refrigerant is not exchanged or mixed with liquid water within chamber 126). As will be understood, sealed refrigeration system 150 may include additional components (e.g., at least one additional evaporator, compressor, expansion device, or condenser). As illustrated, evaporator 158 is provided on or as part of heat exchanger 130 (e.g., in conductive thermal communication with mold finger(s) 136 to cool the same). Thus, heat exchanger 130 may be disposed along the sealed refrigeration loop.

During freezing operations, within sealed refrigeration system 150, gaseous refrigerant flows into compressor 152, which operates to increase the pressure of the refrigerant and motivates refrigerant through the sealed refrigeration loop. This compression of the refrigerant also raises the refrigerant temperature, which is lowered by passing the gaseous refrigerant through condenser 154. Within condenser 154, heat exchange (e.g., with ambient air takes place) to cool the refrigerant and cause the refrigerant to condense to a liquid state.

Expansion device 156 (e.g., a mechanical valve, capillary tube, electronic expansion valve, or other restriction device) receives liquid refrigerant from condenser 154. From expansion device 156, the liquid refrigerant enters evaporator 158. Upon exiting expansion device 156 and entering evaporator 158, the liquid refrigerant drops in pressure and vaporizes. Due to the pressure drop and phase change of the refrigerant, evaporator 158 is cool relative to chamber 126. As such, heat is drawn away from mold finger(s) 136 within chamber 126. Thus, evaporator 158 may act as or with heat exchanger 130 to transfer heat (e.g., from mold finger(s) 136 to refrigerant flowing through evaporator 158).

In certain embodiments, ice-making appliance 100 also includes an air handler 160 mounted within (or otherwise in fluid communication with) chamber 126. Air handler 160 may be operable to urge a flow of ambient air across a portion of sealed refrigeration system 150 (e.g., condenser 154 or heat exchanger 130). Moreover, air handler 160 can be any suitable device for moving air. For example, air handler 160 can be an axial fan or a centrifugal fan. In some embodiments, air handler 160 is in operable (e.g., electrical or wireless) communication with controller 142.

In optional embodiments, a hot gas valve 162 is provided in selective thermal or fluid communication with heat exchanger 130 (e.g., at mold finger(s) 136). During releasing operations for releasing ice nugget(s) 116 from mold finger(s) 136, hot gas valve 162 may direct a heated gas (e.g., gaseous refrigerant) through the heat exchanger 130. For instance, hot gas valve 162 may be disposed along the sealed refrigeration loop (e.g., along the fluid path between compressor 152 and expansion device 156). As shown, hot gas valve 162 may be downstream from compressor 152 and upstream from condenser 154. Optionally, hot gas valve 162 may be operative communication with controller 142. Controller 142 may thus control hot gas valve 162 to release a portion of the compressed, high-heat refrigerant to heat exchanger 130 (e.g., to or through mold finger(s) 136). Heat from the heated gas may be conducted to the outer surface of mold finger(s) 136 such that a small inner layer of ice nugget 116 melts against mold finger 136, releasing ice nugget 116 from mold finger 136, as described above.

In additional or alternative embodiments, an electric heating element 164 (e.g., resistive heating element, radiant heating element, etc.) is provided in conductive thermal communication with the mold finger 136. For instance, electric heating element 164 may be mounted to heat exchanger 130 (e.g., within exchange base 132 or mold finger 136). Optionally, electric heating element 164 may be in operative communication with controller 142. Controller 142 may thus control electric heating element 164 to activate and thus generate heat within heat exchanger 130 (e.g., through mold finger(s) 136). Heat from electric heating element 164 may be conducted to the outer surface of mold finger(s) 136 such that a small inner layer of ice nugget 116 melts against mold finger 136, releasing ice nugget 116 from mold finger 136 as described above.

In further additional or alternative embodiments, an insulated mold body 166 is provided on heat exchanger 130 (e.g., about mold finger 136). For instance, insulated mold body 166 may define a vertically-open recess or cavity defining a bottom portion of ice nugget 116. Generally, insulated mold body 166 may include or be formed by any suitable material, such as a silicone or polyurethane.

It is noted that although a Peltier cell 144 and sealed refrigeration system 150 are illustrated in FIGS. 2 and 6, respectively, the components of the illustrated embodiments may be readily added to or exchanged to either embodiment. Moreover, any suitable chiller system may be provided on heat exchanger 130 to freeze ice nuggets 116 at mold finger(s) 136.

Returning again to FIGS. 1 and 2, upper dispenser 110 may be disposed above lower tank 112 and counter 120 or sink 114. An internal passage 140 is defined by upper dispenser 110 downstream from lower tank 112 to receive ice nuggets 116 and liquid water from chamber 126.

Generally, upper dispenser 110 defines one or more outlets through which ice nuggets 116 may be dispensed (e.g., into or towards sink 114). In some embodiments, upper dispenser 110 includes an ice door 168 movably (e.g., pivotably or slidably) mounted adjacent to an ice outlet 170. Specifically, ice door 168 is movable between a closed position and an open position, as illustrated in FIG. 2. In the closed position, ice door 168 may cover ice outlet 170 and restrict access thereto or therefrom. Ice nuggets 116 may thus be prevented from exiting ice outlet 170 by the ice door 168 in the closed position. By contrast, in the open position, ice door 168 may be held apart from ice outlet 170 such that ice nuggets 116 may fall forward (e.g., as motivated by gravity or water pressure) from upper dispenser 110. In other words, in the open position, ice nuggets 116 may be permitted from upper dispenser 110 through the opened ice door 168.

In additional or alternative embodiments, upper dispenser 110 defines a water outlet 172. As shown, water outlet 172 may be spaced apart from ice outlet 170 and ice door 168. Nonetheless, water outlet 172 may be defined in downstream fluid communication with lower tank 112. Water outlet 172 may be defined in fluid parallel to ice outlet 170. Chilled liquid water (e.g., from the remaining or additional volume of liquid water) may thus be permitted to flow from lower tank 112 and upper dispenser 110 (e.g., to sink 114) through water outlet 172 without passing through ice outlet 170. Optionally, an internal grate may be disposed upstream from water outlet 172 (e.g., above water outlet 172) such that ice nuggets 116 are prevented from flowing to or blocking water outlet 172. Additionally or alternatively, a liquid valve 174 may be provided on or within water outlet 172 such that the flow of liquid water through water outlet 172 may be selectively restricted. In other words, a user may be permitted to open liquid valve 174, such as to dispense a chilled water flow 118 through water outlet 172 separately from ice nuggets 116 or without simultaneously dispensing ice nuggets 116.

Referring now to FIG. 7, various methods (e.g., method 700) may be provided for use with the ice-making appliance 100 in accordance with the present disclosure. In some embodiments, such as the exemplary embodiments illustrated by method 700, all or some of the various steps of the methods may be performed by controller 142 (e.g., as part of an ice-making cycle). For example, controller 142 may, as discussed, be operably coupled to or in operative communication with heat exchanger 130 (e.g., Peltier cell 144), sealed refrigeration system 150, water supply valve 128, pump 137, hot gas valve 162, or electric heating element 164. During use, controller 142 may send signals to receive signals from some or all of these components. Controller 142 may further be operably coupled to or in operative communication with other suitable components of the appliance 100 to facilitate operation of the appliance 100 generally. Present methods may advantageously facilitate the dispensing or formation of substantially clear ice nuggets 116. Moreover, such methods may advantageously permit ice nuggets 116 to be dispensed without the need for any auger or conveying mechanism.

As shown in FIG. 7, at 710, the method 700 includes supplying an initial volume of liquid water to the lower tank. Generally, the initial volume of water may be supplied to the chamber of the lower tank from a water source, as described above. For instance, a water valve may be opened to permit at least a portion of the chamber to fill (e.g., at least a level above the mold finger(s)). The water may be supplied below the sink. Optionally, the initial volume of water may fill the chamber, the vertical passage, and internal passage of the upper dispenser. Additionally or alternatively, the initial volume of water may be supplied while the heat exchanger remains inactive (e.g., turned off or provided at a temperature above 0° Celsius at the mold finger(s)).

At 720, the method 700 includes freezing a portion of the initial volume of liquid water as an ice nugget on one or more mold fingers within a remaining volume of the initial volume of liquid water. In other words, less than all of the initial volume of water will freeze as the ice nugget and will be surrounded by the rest of the initial volume of water, which remains in liquid form.

Generally, the freezing at 720 requires lowering the temperature of the mold finger(s) below the freezing temperature of the initial volume of water (e.g., below 0° Celsius). A suitable chiller system or assembly may be provided on or as part of the heat exchanger, as described above. For instance, if a Peltier cell is provided with heat exchanger, the Peltier cell may be activated to conduct heat away from the mold finger(s) and to the hot side of the cell, which may be disposed outside of the chamber of the lower tank (e.g., such that heat can be rejected to the ambient environment). Additionally or alternatively, if a sealed refrigeration system is provided with heat exchanger, the compressor of the sealed refrigeration system may be activated to motivate the refrigerant through the heat exchanger, as described above.

In optional embodiments, water (e.g., the remaining volume of water) is circulated within the chamber during 720. Thus, the water within lower tank can be prevented from remaining static as the ice nugget freezes. For instance, the pump may be activated to move or circulate the remaining volume of water through or within the chamber as the ice nugget forms.

At 730, method 700 includes releasing the ice nugget from the mold finger. For instance, following 720, 730 may include heating the mold finger, as described above. In some embodiments, heating includes directing a heated gas through the heat exchanger (e.g., from the hot gas valve of the sealed refrigeration system). In additional or alternative embodiments, an electric heating element on or in conductive thermal communication with the heat exchanger is activated. In further additional or alternative embodiments, the Peltier cell may be activated. Optionally, the current flow through the Peltier cell may be reversed from a direction during freezing. In other words, the Peltier cell may direct heat to the mold finger(s) from a cold side outside of the chamber.

At 740, the method 700 includes permitting the ice nugget to float upward from the mold finger to the upper dispenser. For instance, the ice nugget may float freely and unobstructed through the vertical passage and into the internal passage of the upper dispenser (e.g., without any assistance from an auger or mechanical conveyer mechanism). Optionally, additional water may be supplied to the lower tank to help lift the ice nugget. For instance, if the initial volume of water does not fill the entire region from the chamber to the internal passage of the upper dispenser, the additional volume of water may be required to permit the ice nugget(s) to float all the way to the upper dispenser.

Once the ice nugget has floated to the upper dispenser, the ice nugget or water within upper dispenser may be dispensed. For instance, an ice door of the upper dispenser may be opened, and the ice nugget may be permitted from the upper dispenser through the upper dispenser. Additionally or alternatively, a liquid valve may be opened to permit a chilled-water flow (e.g., of the remaining volume or additional water lifting the ice nugget) may be permitted from the upper dispenser through the water outlet (e.g., separately and apart from the ice nugget). Following dispensing, the ice door or liquid valve may again be closed such that further ice or water is prevented from escaping the upper dispenser.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

1. An ice-making assembly comprising: a sink; an upper dispenser disposed above the sink, the upper dispenser defining an ice outlet and an internal passage extending to the ice outlet; a lower tank disposed below the upper dispenser to hold an initial volume of liquid water upstream from the upper dispenser; and a heat exchanger comprising a mold finger disposed within the lower tank and to freeze a portion of the initial volume of liquid water as an ice nugget, wherein the lower tank defines a vertical passage upstream from the internal passage thereby permitting the ice nugget to float through the vertical passage and internal passage within a remaining volume of liquid water, and wherein the upper dispenser comprises an ice door, the ice door being movable between a closed position and an open position, the open position permitting the ice nugget from the upper dispenser to the sink through the ice outlet.
 2. The ice-making assembly of claim 1, further comprising: a pump disposed within the lower tank to selectively circulate the remaining volume of liquid water.
 3. The ice-making assembly of claim 1, further comprising: a controller in operative communication with the heat exchanger, the controller being configured to initiate an ice-making cycle, the ice-making cycle comprising releasing the ice nugget from the mold finger, releasing comprising directing a heated gas through the heat exchanger.
 4. The ice-making assembly of claim 1, further comprising: an electric heating element in conductive thermal communication with the mold finger; and a controller in operative communication with the heat exchanger and the electric heating element, the controller being configured to initiate an ice-making cycle, the ice-making cycle comprising releasing the ice nugget from the mold finger, releasing comprising activating the electric heating element to heat the mold finger.
 5. The ice-making assembly of claim 1, wherein the heat exchanger comprises a Peltier cell in conductive thermal communication with the mold finger, and wherein the ice-making assembly further comprises: a controller in operative communication with the heat exchanger and the Peltier cell, the controller being configured to initiate an ice-making cycle, the ice-making cycle comprising releasing the ice nugget from the mold finger, releasing comprising activating the Peltier cell to heat the mold finger.
 6. The ice-making assembly of claim 1, wherein the heat exchanger comprises a Peltier cell in conductive thermal communication with the mold finger, and wherein the ice-making assembly further comprises: a controller in operative communication with the heat exchanger and the Peltier cell, the controller being configured to initiate an ice-making cycle, the ice-making cycle comprising freezing the ice nugget on the mold finger, the freezing comprising activating the Peltier cell to conduct heat away from the mold finger.
 7. The ice-making assembly of claim 1, further comprising: a sealed refrigeration loop in fluid isolation from the lower tank to circulate a refrigerant through the sealed refrigeration loop, the heat exchanger being disposed along the sealed refrigeration loop; and a compressor disposed on the sealed refrigeration loop in fluid communication with the heat exchanger to motivate the refrigerant thereto.
 8. The ice-making assembly of claim 1, wherein the upper dispenser defines a water outlet spaced apart from the ice door, the water outlet being in downstream fluid communication with the lower tank to direct a chilled-water flow from the remaining volume of liquid water.
 9. The ice-making assembly of claim 1, further comprising: a water supply valve in upstream fluid communication with the lower tank; and a controller in operative communication with the heat exchanger and the water supply valve, the controller being configured to initiate an ice-making cycle, the ice-making cycle comprising supplying the initial volume of liquid water to the lower tank through the water supply valve, freezing the portion of the initial volume of liquid water as the ice nugget on the mold finger within the remaining volume of liquid water, releasing the ice nugget from the mold finger, and permitting the ice nugget to float upward from the mold finger to the upper dispenser.
 10. A method of dispensing ice from a lower tank through an upper dispenser defining an ice outlet and an internal passage extending to the ice outlet, the lower tank defining a vertical passage and enclosing a mold finger of a heat exchanger below the upper dispenser, the method comprising: supplying an initial volume of liquid water to the lower tank; freezing a portion of the initial volume of liquid water as an ice nugget on the mold finger within a remaining volume of the initial volume of liquid water; releasing the ice nugget from the mold finger; and permitting the ice nugget to float upward from the mold finger through the vertical passage and the internal passage to the ice outlet.
 11. The method of claim 10, further comprising circulating the remaining volume of water through a pump in fluid communication with the lower tank during freezing.
 12. The method of claim 10, wherein releasing the ice nugget comprises heating the mold finger.
 13. The method of claim 12, wherein heating the mold finger comprises directing a heated gas through the heat exchanger.
 14. The method of claim 12, wherein heating the mold finger comprises activating an electric heating element in conductive thermal communication with the mold finger.
 15. The method of claim 12, wherein heating the mold finger comprises activating a Peltier cell in conductive thermal communication with the mold finger.
 16. The method of claim 10, freezing wherein freezing comprises activating a Peltier cell in conductive thermal communication with the mold finger.
 17. The method of claim 10, wherein freezing comprises activating a compressor of a sealed refrigeration system to motivate refrigerant through the heat exchanger.
 18. The method of claim 10, further directing a chilled-water flow through a water outlet on the upper dispenser from the remaining volume of liquid water within the lower tank.
 19. The method of claim 10, further comprising: opening an ice door at a top end of the upper dispenser; and permitting the ice nugget from the upper dispenser through the opened ice door.
 20. An ice-making assembly comprising: a sink; an upper dispenser disposed above the sink, the upper dispenser defining an ice outlet, a water outlet in fluid parallel to the ice outlet, and an internal passage extending to the ice outlet and the water outlet, the upper dispenser comprising an ice door selectively covering the ice outlet; a lower tank disposed below the upper dispenser to hold an initial volume of liquid water upstream from the upper dispenser, the lower tank defining a vertical passage upstream from the internal passage; a heat exchanger comprising a mold finger disposed within the lower tank and to freeze a portion of the initial volume of liquid water as an ice nugget; a water supply valve in upstream fluid communication with the lower tank; and a controller in operative communication with the heat exchanger and the water supply valve, the controller being configured to initiate an ice-making cycle, the ice-making cycle comprising supplying the initial volume of liquid water to the lower tank through the water supply valve, the initial volume of liquid water filling the vertical passage and the internal passage, freezing the portion of the initial volume of liquid water as the ice nugget on the mold finger within a remaining volume of liquid water, releasing the ice nugget from the mold finger, and permitting the ice nugget to float from the mold finger within the remaining volume of liquid water through the vertical passage and the internal passage to the ice outlet via buoyancy. 